EXPERIENCE WITH CDK4/6 INHIBITORS: A SINGLE INSTITUTION STUDY


Year:

Session type:

Theme:

Sarah Saeed Qureshi1,Muhammad Farooq Latif1,Syed Hammad Tirmazy1
1Dubai Hospital

Abstract

Background

CDK4/6 inhibitors have been approved for the treatment of hormone receptor positive (HR+), HER2 negative metastatic breast cancer in combination with hormonal therapy. 

There is limited experience with these drugs in this region. The objective of this study was to analyze progression-free survival and adverse events in our heterogenous patient population.

Method

This is a retrospective study of 30 patients who received CDK4/6 inhibitors in any line of therapy at the Department of Oncology, Dubai Hospital, between September 2015 to February  2019. Median PFS was determined. Toxicities were extracted from medical records.

Results

Thirty patients were included in this study. Twenty-eight patients received Palbociclib and two patients were put on Ribociclib. Median age was 54.5 years (range 31-79 years). Fourteen patients had de-novo metastatic disease. Sixteen patients received these drugs as first-line therapy. Nineteen patients had visceral disease while 11 had bone-only metastasis. Nineteen patients received CDK4/6 inhibitors in combination with an aromatase inhibitor and 11 patients with Faslodex. Median duration of treatment was 10 months. Response was assessed in 26 patients. Two patients achieved complete response. Partial response was seen in eight patients. 10 patients had stable disease. Response has not been assessed in four patients. The most common adverse event to be reported was neutropenia, seen in 16 patients. Dose was reduced in seven patients. Treatment was interrupted in ten patients. One patient receiving ribociclib developed vitiligo.  Median PFS was 10 months.

Conclusion

CDK4/6 inhibitors are effective and well tolerated among all age groups of our patients.  Neutropenia is the most frequent adverse event reported, which was uncomplicated and managed with treatment interruption for a short period. No serious side effects were observed. Continued use of these drugs will enhance our experience, leading to selection of patients who can derive the most benefit from this class of drugs.